Television



May 26, 1931.. MERTZ 1,806,638

' TELEVISION Filed July 24, 1928 IN VENTOI? HERRE MEET;

I ATTORNEY I Patented May 26, 1931 UNITED STATES PATENT OFFICE PIERREmm, 01 IBELLEBDSE MANOR, NEW YORK, ASSIGNOR TO AMERICAN TELE- PHONE ANDTELEGRAPH COMPANY, A CORPORATION 01' NEW YORK TELEVISION Application11101! July 84, 1928. Seriallfo. 895,098.

This invention relates to electro-optical systems and more particularlyto television. The principal object of this invention is Y to improvethe resolution in electro-optical 5 image producing s stems.

In accordance with the invention, this object is in general accomplishedby moving the image elements from one scanning to the next to causeoverlapping. The distor- 1 ning. Consequently, if the eye viewing theimage averages the impression from several successive scannings, thedistortion visible to it is in general less than if the elements shouldremain fixed from scanning to scanning.

2o In a'specific arrangement,.which is illustrative of the invention,the scanning discs at both the transmitter and the receiverof atelevision system such, for example, as the system disclosed in an aplication of H. E.

Ives and Frank Gray, erial No. 181,511, filed April 6, 1927, are eachprovided with two sets of spirally arranged apertures, one set on eachhalf of the disc. One set is adapted to scan an image field in aplurality of adjacent elemental'line traces. Theother set then scans thesame field also in a plurality of line traces but each of these tracesoverlaps-ad'acent portions of two adjacent traces scanne b the firstset. Thus, for each revolution o the scanning disc, two successivescannings are accomplished and the image elements are moved from oneseaming to the next.

This invention is not limited to television systems but is usablewherever optical images are produced by multiple exposures of an imagefield by the exposure of elemental areas thereof.

The invention will now be described more in detail, having reference tothe accompanyin drawings.

igure 1 shows schematically a television Fig. 2 is a scanning disc foruse in the sys- 60 tom of Fig. 1, and Flg. 3 is a schematic diagramshowing the relation of the lines scanned by the two sets of aperturesshown in Fig. 2. Y

In the system of Fig. 1 the television transmitter T is associated witha cooperating receive'r R by a transmission channel such as the line L.Reference may be had to the aplication of Messrs. Ives and Gray supra,for

urther details of equipment suitable for use in the system of Fig. 1,with the exception of the scanning disc, details of which are shown inFig. 2.

As the scanning discs rotate, elemental lines of the image field arescanned in succession. A complete scanning as herein used is one inwhich the scanning path pattern is complete.

In systems heretofore known, complete scannings have covered eitheridentical elemental areas or non-overlapping elemental areas. In thepresent invention, as observa tion of Figs. 2 and 3 discloses, the pathsof complete scannings partially overlap.

In the disc 5 of Fig. 2 only five apertures are shown to effect acomplete scanmng. In actual practice, a larger number of apertures is ingeneral used, the smaller number being shown herein for purpose ofsimplification. Apertures 6 to 10 produce one complete scanning during ahalf revolution of the disc 5 while apertures 11 to 15 roduce anotherscanning during the next hal revolution. As shown by the dotted lines,aperture 11 follows a path partially overlapping the paths followed byapertures 6 and 7. Overlapping of the paths likewise occurs for theother apertures. The relation of these overlapping paths is shown inFig. 3. The numbers 11, 12, 13, 14 and 15 represent paths whichpartially overlap the paths represented by the dotted lines and numbersdirectly opposite; for example, path 12 overlaps portions of paths 11,8, and 7, represented by the three dotted lines opposite these numbers.

A further improvement in resolution of the produced image may beeffected by providing more than'two sets of a ertures for the disc 5. Itis then necessary t at the positionsof the paths for successivescannings 100 of two. lines of the trace of t be in some irregularorder, as a regular order might cause an apparent motion of the pictureelements in the viewing field which would be annoying. The extent towhich improvement can be effected in thls manner will depend upon thenumber of successive scannings over which the average is taken by theeye in determinin its impression.

The invention is, 0 course, not limited to the articular arrangementdescribed in detail ut is defined by the scope of the appended claims.

What is claimed is:

1. The method of scanning to produce image'currents which comprisesrepeatedly scanning the entire area of a field of view and causing eachscanning line of the entire path of one complete scannin to partiallyoverlap two scanning lines o a preceding one. I

2. The method of scanning to produce image currents which comprisesrepeatedly scanning the entire area of a field of view and cyclicallyshifting the scanning path between complete scannings so that eachscanning line of a complete path partially overlaps two scanning lmes ofa preceding one.

3. In an electro-optical system means to repeatedly scan the entire areaoi a field of view along line series of elemental areas thereof,comprising means for causin each scanning to traverse a trace each hneof which overlaps simultaneously portions only e preceding scanning.

4. In an electro-optical system means to repeatedly scan the entire areaof a field of view along line series of elemental areas thereof,comprising means for causing each scanning to traverse a trace each hneof which overlaps simultaneously .at least onehalf of each of twoadjacent lines of the trace of the preceding scanning.

5. In an electro-optical system, means for repeatedly successivelyscanning contiguous line series of elemental areas of the entire area ofa field of view, said means c o mprising a scanning member having aplurality of setsof scanning apertures so placed that each line scannedby one set overlaps substantially half of two lines scanned by anotherset.

6. In an image producing system, a scanning disc, a set of a of saiddisc arrange to scan the entire area of an ignage field in a pluralityof elemental lines as the disc rotates, and a second set of apertureson-another portion of said disc arranged to scan the entire area of thesame image field and radially displaced with respect to the first set ofapertures by a substantial portion of the diameter of the aper- 7 oneset of tures so that each line scanned by f f al 0 two aperturesoverlaps substantially lines scanned by the other set.

7. The method of scanning to produce of said disc arran e field, andcausing each km of the entire rtures on one portion image currents whichcomprises scanning the entire area of a field of view, and a ainscanning substantially the entire area 0 said field of view in such amanner that each line traced by the second scanning overlaps porti 0nsof two lines traced by the first scanning.

' 8. The method of scanning to produce image currents which comprisesrepeatedly completely scanning with overlapping lines, the entire areaof a field of view, and cyclicall shifting the scanning path after eachcomp ete scanning so that each line of a succeeding scanning overlapsportions of two lines overlapped in the previous scanning.

9. In an electro-optical system, means for repeatedly successivelyscanning contiguous line series of elemental areas of the entire area ofa field of view, said means comprising a scanning member having a set ofscanning a rtures so placed that the line scanned by eac aperture isartially overlapped by the line scanned by t e next succeeding aperture,and having an additional set of scanning apertures so placed that theline scanned by each of these apertures partially overlaps two of theoverlapped lines scanned by the first mentioned set of scanningapertures.

10. In an image producing system, a scanning disc, aset of a ertures onone ortion to scan as the iso rotates an'image fiel in a plurality ofelemental lines, each one of which partially overlaps thepreceding line,and a second set of apertures on another portion of said discarranged'to scan the same image field and radially displaced withrespect to the first set of apertures b a substantial portion of thediameter of t e apertures so that the line traced by each of theseapertures overlaps portions of the overlapped lines of the firstmentioned set of apertures. I

11. The method of scanning to produce image currents which comprisesrepeatedly completely scanning the entire area of a field of view, thetraces produced by each complete scanning completely covering thls at ofone complete scanning to only parti all overlap two lines of the path ofthe preced ing scannin j 12. The method of scanning'to produce imagecurrents which comprises scanning the entire area of a field of view bycausing each scanning line to partially overlap that of a preceding one,and again scanning substantially the entire area of said field of viewby lines which overlap each other and also overlap portions of linesoverlapped in the first scann ng.

In testimony whereof, I have signed my name to this specification this6th day of July, 1928.

PIERRE MERTZ.

